Relationships between individual animal variation in dry matter intake and animal performance and feed efficiency of finishing beef cattle

Objective: The objective of this experiment was to evaluate the relationship between 2 measures of daily individual animal variation in DMI with measures of overall DMI, ADG, carcass traits, and feed efficiency of finishing beef cattle. Materials and Methods: Daily DMI data were collated from 3 previously published experiments within which beef cattle were individually fed using a Calan gate system (American Calan, Northwood, NH) or an Insentec Roughage Intake Control system (Hokofarm Group, Emmeloord, the Netherlands). The day-to-day CV for DMI of each animal was calculated. Next, the average Euclidian distance (ED) was calculated. The Pearson's (rp) and Spearman's (rs) correlations between CV and ED methods and production traits and efficiency indexes were calculated. Results and Discussion: The CV was inversely correlated with DMI (rp = -0.65; rs = -0.59), ADG (rp = -0.52; rs = -0.52), and residual feed intake (rp = -0.41; rs = -0.35) and positively correlated with residual intake and gain (rp = 0.29; rs = 0.25). The CV was negatively correlated with hot carcass weight (HCW; rp = -0.46; rs = -0.45), back fat thickness (rp = -0.25; rs = -0.31), yield grade (rp = -0.29; rs = -0.31), and calculated empty body fat (rp = -0.30; rs = -0.32). The ED was negatively correlated with ADG (rp = -0.55; rs = -0.61), G:F (rp = -0.49; rs = -0.50), residual ADG (rp = -0.57; rs = -0.56), and HCW (rp = -0.33; rs = -0.39). Implications and Applications: The 2 measures of DMI variation appear to divergently explain variation in DMI and the relationship with production traits and feed efficiency. However, cattle with more improved production outcomes were associated with less day-to-day variation in DMI.